Deflectable catheter shaft section, catheter incorporating same, and method of manufacturing same

ABSTRACT

A deflectable catheter shaft section is disclosed comprising an elongated body extending along a longitudinal axis and comprising a distal end and a proximal end; and a plurality of lumens extending along the longitudinal axis of the elongated body, wherein at least one of the lumens is abutting at least another one of the lumens. A catheter comprising the deflectable catheter shaft section and a method of manufacturing the deflectable catheter shaft section are also disclosed. A catheter incorporating a deflectable catheter shaft section can further comprise first and second compression coils disposed over pull wires located within the catheter, wherein the compression coils are unattached to the catheter or components thereof, but can be constrained by a shaft coupler at a distal end of each of the compression coils and by at least a portion of a handle assembly at a proximal end of each of the compression coils.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of U.S. application Ser. No. 14/333,235,filed 16 Jul. 2014 (the '235 application), which is a divisional of U.S.application Ser. No. 13/838,124, filed 15 Mar. 2013 (the '124application), now U.S. Pat. No. 8,814,825, which claims the benefit ofU.S. provisional application No. 61/643,748, filed 7 May 2012 (the '748application). This application is related to U.S. nonprovisionalapplication Ser. No. 13/836,846, being filed on the same day as the '124application, and also claiming the benefit of the '748 application. The'235 application, the '124 application, and the '748 application are allhereby incorporated by reference as though fully set forth herein.

BACKGROUND OF THE INVENTION a. Field of the Invention

The instant disclosure relates generally to a deflectable catheter shaftsection, a catheter incorporating such a deflectable catheter shaftsection, and a method of manufacturing such a deflectable catheter shaftsection.

b. Background Art

Electrophysiology catheters are used in a variety of diagnostic,therapeutic, and/or mapping and ablative procedures to diagnose and/orcorrect conditions such as atrial arrhythmias, including for example,ectopic atrial tachycardia, atrial fibrillation, and atrial flutter.Arrhythmias can create a variety of conditions including irregular heartrates, loss of synchronous atrioventricular contractions and stasis ofblood flow in a chamber of a heart which can lead to a variety ofsymptomatic and asymptomatic ailments and even death.

Typically, a catheter is deployed and manipulated through a patient'svasculature to the intended site, for example, a site within a patient'sheart or a chamber or vein thereof. The catheter carries one or moreelectrodes that can be used for cardiac mapping or diagnosis, ablationand/or other therapy delivery modes, or both, for example. Once at theintended site, treatment can include, for example, radio frequency (RF)ablation, cryoablation, laser ablation, chemical ablation,high-intensity focused ultrasound-based ablation, microwave ablation,and/or other ablation treatments. The catheter imparts ablative energyto cardiac tissue to create one or more lesions in the cardiac tissueand oftentimes a contiguous or linear and transmural lesion. This lesiondisrupts undesirable cardiac activation pathways and thereby limits,corrals, or prevents errant conduction signals that can form the basisfor arrhythmias.

To position a catheter within the body at a desired site, some type ofnavigation must be used, such as using mechanical steering featuresincorporated into the catheter (or an introducer sheath). In someexamples, medical personnel may manually manipulate and/or operate thecatheter using the mechanical steering features.

In order to facilitate the advancement of catheters through a patient'svasculature, the simultaneous application of torque at the proximal endof the catheter and the ability to selectively deflect the distal tip ofthe catheter in a desired direction can permit medical personnel toadjust the direction of advancement of the distal end of the catheterand to position the distal portion of the catheter during anelectrophysiological procedure. The proximal end of the catheter can bemanipulated to guide the catheter through a patient's vasculature. Thedistal tip can be deflected by a pull wire attached at the distal end ofthe catheter that extends to a control handle that controls theapplication of tension on the pull wire.

Two of the mechanical considerations for a catheter shaft are that ittransmit torque and resist compression during use. With respect totransmitting torque, medical personnel normally navigate the distal endof the catheter to a desired location in part by manipulating a handledisposed at the proximal end of the catheter. Substantial frictionalforces sometimes resist transmission of torque across the length of thecatheter. In some cases, these forces can cause the catheter shaft totwist about a longitudinal axis of the catheter shaft, storing energy inthe process in a spring-like fashion. If the energy is releasedsuddenly, the distal end of the catheter, which may be deflected by asteering mechanism, can be undesirably propelled with significant force.

With respect to resisting compression during use, it is important formedical personnel to be able to advance the catheter through a vessel,sometimes against significant frictional resistance, without undue axialcompression or snaking of the catheter shaft. Shaft compression canresult in a loss of control for the medical practitioner and cancomplicate the positioning of the distal end of the catheter shaft at adesired location for a medical procedure. In addition, medical personnelmay rely on tactile feedback to attain and verify proper positioning ofthe catheter, and such feedback can be impaired by excessivecompressibility.

The foregoing discussion is intended only to illustrate the presentfield and should not be taken as a disavowal of claim scope.

BRIEF SUMMARY OF THE INVENTION

In various embodiments, a deflectable catheter shaft section cancomprise an elongated body extending along a longitudinal axis andcomprising a distal end and a proximal end; and a plurality of lumensextending along the longitudinal axis of the elongated body, wherein atleast one of the plurality of lumens is abutting at least another one ofthe plurality of lumens. Each of the plurality of lumens can be abuttingat least another one of the plurality of lumens in embodiments of theinvention. The deflectable catheter shaft section can further comprise aplurality of liners corresponding to each of the plurality of lumens,wherein each of the plurality of liners is comprised ofpolytetrafluoroethylene (PTFE). Each of the plurality of lumens can beless than about 0.015 inches from another of the plurality of lumens inaccordance with some embodiments of the invention.

In various embodiments, a catheter can comprise a deflectable cathetershaft section comprising an elongated body extending along alongitudinal axis and comprising a distal end and a proximal end; and aplurality of lumens extending along the longitudinal axis of theelongated body, wherein at least one of the plurality of lumens isabutting at least another one of the plurality of lumens; and a proximalcatheter shaft section disposed at the proximal end of the deflectablecatheter shaft section. Each of the plurality of lumens can be abuttingat least another one of the plurality of lumens in embodiments of theinvention. Each of the plurality of lumens can be less than about 0.015inches from another of the plurality of lumens in accordance with someembodiments of the invention. The catheter can further comprise aplurality of liners corresponding to each of the plurality of lumens ofthe deflectable catheter shaft section, wherein each of the plurality ofliners is comprised of PTFE.

In at least one embodiment, the deflectable catheter shaft section cancomprise a first pocket located at the distal end and a second pocketlocated at the proximal end. The catheter can further comprise a tipassembly disposed at the distal end of the deflectable catheter shaftsection in the first pocket and a handle assembly comprising an actuatorconfigured to effect movement of the deflectable catheter shaft section.The catheter can further comprise a pull ring disposed in the firstpocket and at least two pull wires attached to diametrically oppositelocations on the pull ring, wherein the pull wires extend from the pullring toward the handle assembly. The catheter can further comprise ashaft coupler disposed in the second pocket. The shaft coupler can begenerally cylindrical in shape and can comprise an outer radial surfacecomprising a helical groove.

In at least one embodiment, the catheter can further comprise first andsecond compression coils each disposed over one of the at least two pullwires, wherein each of the first and second compression coils comprisesa proximal end and a distal end, wherein the distal end of each of thefirst and second compression coils abuts and is constrained by the shaftcoupler, and wherein the proximal end of each of the first and secondcompression coils abuts and is constrained by at least a portion of thehandle assembly. The first and second compression coils can beunattached to the proximal catheter shaft section. The first and secondcompression coils can be unattached to the shaft coupler. The first andsecond compression coils can be unattached to the handle assembly.

In various embodiments, a method of manufacturing a deflectable cathetershaft section can comprise the steps of providing a plurality ofmandrels; providing a mandrel alignment tool comprising a plurality ofslots, each of the plurality of slots configured for housing at least aportion of one of the plurality of mandrels; placing a plurality offirst polymeric tubes over the plurality of mandrels; providing toolingconfigured to hold the mandrel alignment tool, wherein the toolingcomprises a plurality of pairs of opposing tensioning blocks, each ofthe plurality of pairs of opposing tensioning blocks corresponding toone of the plurality of mandrels or the mandrel alignment tool, andwherein each of the plurality of pairs of opposing tensioning blocks isconfigured to place one of the plurality of mandrels under tension andrelease one of the plurality of mandrels from tension; attaching each ofthe plurality of mandrels and each of the plurality of first polymerictubes to one of the plurality of pairs of opposing tensioning blocks;tensioning each of the plurality of mandrels; and releasing tension ofeach of the plurality of mandrels. In accordance with an embodiment ofthe invention, the step of providing a mandrel alignment tool comprisinga plurality of slots comprises wire cutting from one of the plurality ofslots to another of the plurality of slots. In accordance with anembodiment of the invention, each of the plurality of first polymerictubes comprises PTFE.

In at least one embodiment, the method of manufacturing a deflectablecatheter shaft section can further comprise the steps of placing acylindrical braid structure over the plurality of mandrels and theplurality of first polymeric tubes; stretching the cylindrical braidstructure; and placing at least one second polymeric tube over thecylindrical braid structure. In accordance with an embodiment of theinvention, the at least one second polymeric tube comprisespolyurethane, nylon, or polyether block amides.

In at least one embodiment, the method of manufacturing a deflectablecatheter shaft section can further comprise the steps of placing a heatshrink tube over the at least one second polymeric tube so that the heatshrink tube covers at least a portion of the mandrel alignment tool;subjecting the tooling, the plurality of mandrels, the plurality offirst polymeric tubes, the cylindrical braid structure, the at least onesecond polymeric tube, and the heat shrink tube to a heating process;and reflowing at least a portion of the deflectable catheter shaftsection. In accordance with an embodiment of the invention, the methodof manufacturing a deflectable catheter shaft section can furthercomprise the step of pre-shrinking the heat shrink tube, wherein thestep of pre-shrinking the heath shrink tube can comprise applying heatwith a heat gun. The method of manufacturing a deflectable cathetershaft section can further comprise the steps of: removing the pluralityof mandrels; removing the heat shrink tube; and trimming at least aportion of the deflectable catheter shaft section to a select length.

The foregoing and other aspects, features, details, utilities, andadvantages of the present disclosure will be apparent from reading thefollowing description and claims, and from reviewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a catheter incorporating a deflectablecatheter shaft section in accordance with an embodiment of theinvention.

FIG. 2A is a partially cut-away isometric view of the deflectablecatheter shaft section of FIG. 1 taken along line 2A-2A, with variouscomponents of the catheter omitted for the purposes of clarity.

FIG. 2B is a cross-sectional view of the deflectable catheter shaftsection of FIG. 1 taken along line 2B-2B seen in FIG. 2A.

FIG. 3 is a longitudinal, side cross-sectional view of the deflectablecatheter shaft section of FIG. 1 taken along line 3-3, with variouscomponents of the catheter omitted for the purposes of clarity.

FIG. 4A is a partially cut-away, isometric view of the deflectablecatheter shaft section of FIG. 1, showing a shaft coupler in accordancewith an embodiment of the invention.

FIG. 4B is a partially cut-away, isometric view of the deflectablecatheter shaft section of FIG. 1 showing a shaft coupler in accordancewith an embodiment of the invention.

FIG. 5 is a transparent, isometric view of the deflectable cathetershaft section of FIG. 1, with various components of the catheter omittedfor the purposes of clarity.

FIG. 6 is an isometric view of the deflectable catheter shaft section ofFIG. 1 and a shaft coupler, pull wires, and compression coils inaccordance with an embodiment of the invention.

FIG. 7 is a partial, isometric view of the deflectable catheter shaftsection of FIG. 1 and a shaft coupler, pull wires, and compression coilsin accordance with an embodiment of the invention.

FIG. 8 is a schematic view of a portion of the deflectable cathetershaft section of FIG. 1, pull wires, and a portion of a handle assemblyin accordance with an embodiment of the invention.

FIG. 9A is a partially cut-away, top view of a handle assembly for acatheter incorporating the deflectable catheter shaft section of FIG. 1in accordance with an embodiment of the invention.

FIG. 9B is a partial, exploded view of the handle assembly of FIG. 9A.

FIGS. 10A-10C are partial, isometric views of mandrels and a mandrelalignment tool for manufacturing the deflectable catheter shaft sectionof FIG. 1 in accordance with an embodiment of the invention.

FIG. 11 is a partial, isometric view of a mandrel alignment tool formanufacturing the deflectable catheter shaft section of FIG. 1 inaccordance with an embodiment of the invention.

FIG. 12 is a fragmentary, isometric view of mandrels with surroundingpolymeric tubes over them for manufacturing the deflectable cathetershaft section of FIG. 1 in accordance with an embodiment of theinvention.

FIG. 13 is an isometric view of tooling for manufacturing thedeflectable catheter shaft section of FIG. 1 in accordance with anembodiment of the invention.

FIG. 14 is a partial, isometric view of tooling for manufacturing thedeflectable catheter shaft section of FIG. 1 in accordance with anembodiment of the invention.

FIG. 15 is a partial, isometric view of tooling for manufacturing thedeflectable catheter shaft section of FIG. 1 in accordance with anembodiment of the invention.

FIG. 16 is an isometric view of an alternative embodiment to the shaftcoupler shown to good advantage in FIGS. 4A, 4B, and 7.

FIG. 16A is similar to FIG. 16 and is an isometric view of an anotheralternative shaft coupler.

FIG. 17 is a fragmentary view of a deflectable catheter shaft sectionand an intermediate catheter shaft section.

FIG. 18 is a cross-sectional view taken along line 18-18 of FIG. 17.

FIG. 19 is an end view taken in the direction of line 19-19 of FIG. 18.

FIG. 20 is an enlarged view of circled region CC shown in FIG. 18.

FIG. 21 is an enlarged, fragmentary, cross-sectional view of a portionof the deflectable catheter shaft section depicted in FIGS. 17 and 18,and includes an enlarged view of the region within dashed circle AA ofFIG. 18.

FIG. 22 is a fragmentary, isometric view of a distal shaft couplermounted in the longitudinal end of an intermediate catheter shaftsection, and depicts short sections of the first and second pull wiresextending from the distal end of the distal shaft coupler.

FIG. 23 is an isometric view of a bendable stiffening member, whichinclude in this embodiment a coil support tube and a multi-pitch coil.

FIG. 24 is an isometric view of a multi-pitch coil.

FIGS. 25 and 26 depict two additional views of the multi-pitch coildepicted in FIG. 24.

FIG. 27 is an end view of the multi-pitch coil taken along line 27-27 ofFIG. 26.

FIG. 28 is an enlarged, fragmentary view of a portion of the coildepicted in FIGS. 24-27.

DETAILED DESCRIPTION OF THE DISCLOSURE

Embodiments are described herein of various apparatuses, systems, and/ormethods. Numerous specific details are set forth to provide a thoroughunderstanding of the overall structure, function, manufacture, and useof the embodiments as described in the specification and illustrated inthe accompanying drawings. It will be understood by those skilled in theart, however, that the embodiments may be practiced without suchspecific details. In other instances, well-known operations, components,and elements have not been described in detail so as not to obscure theembodiments described in the specification. Those of ordinary skill inthe art will understand that the embodiments described and illustratedherein are non-limiting examples, and thus it can be appreciated thatthe specific structural and functional details disclosed herein may berepresentative and do not necessarily limit the scope of theembodiments, the scope of which is defined solely by the appendedclaims.

Reference throughout the specification to “various embodiments,” “someembodiments,” “one embodiment,” or “an embodiment”, or the like, meansthat a particular feature, structure, or characteristic described inconnection with the embodiment(s) is included in at least oneembodiment. Thus, appearances of the phrases “in various embodiments,”“in some embodiments,” “in one embodiment,” or “in an embodiment,” orthe like, in places throughout the specification, are not necessarilyall referring to the same embodiment. Furthermore, the particularfeatures, structures, or characteristics may be combined in any suitablemanner in one or more embodiments. Thus, the particular features,structures, or characteristics illustrated or described in connectionwith one embodiment may be combined, in whole or in part, with thefeatures, structures, or characteristics of one or more otherembodiments without limitation given that such combination is notillogical or non-functional.

It will be appreciated that the terms “proximal” and “distal” may beused throughout the specification with reference to a clinicianmanipulating one end of an instrument used to treat a patient. The term“proximal” refers to the portion of the instrument closest to theclinician and the term “distal” refers to the portion located furthestfrom the clinician. It will be further appreciated that for concisenessand clarity, spatial terms such as “vertical,” “horizontal,” “up,” and“down” may be used herein with respect to the illustrated embodiments.However, surgical instruments may be used in many orientations andpositions, and these terms are not intended to be limiting and absolute.

FIG. 1 generally illustrates a deflectable electrophysiology catheter 10that comprises a deflectable catheter shaft section 12 in accordancewith an embodiment of the invention. Deflectable catheter shaft section12 comprises an elongated body having a distal end 14 and a proximal end16. In its most general form, catheter 10 further comprises a tipassembly 18 located at the distal end 14 of the deflectable cathetershaft section 12, a proximal catheter shaft section 20 located at theproximal end 16 of the deflectable catheter shaft section 12, and ahandle assembly 22. Catheter 10 may be used in any number of diagnosticand therapeutic applications, such as the recording of electrograms inthe heart, the performance of a cardiac ablation procedure, and othersimilar applications/procedures. Accordingly, one of ordinary skill inthe art will recognize and appreciate that the inventive deflectablecatheter shaft section and method of manufacturing the same can be usedin any number of diagnostic and therapeutic applications.

Still referring to FIG. 1, deflectable catheter shaft section 12 isdisposed between the tip assembly 18 and the proximal catheter shaftsection 20. The length and diameter of the deflectable catheter shaftsection 12 can vary according to the application. Generally, the lengthof the deflectable catheter shaft section 12 can range from about 2inches (50.8 mm) to about 6 inches (152.4 mm) and the diameter of thedeflectable catheter shaft section 12 can range from about 5 French toabout 12 French. The diameter of the deflectable catheter shaft section12 can be about 7 French in accordance with some embodiments of theinvention. Although these particular dimensions are mentioned inparticular, the dimensions of the deflectable catheter shaft section 12can vary in accordance with various applications of the deflectablecatheter shaft section 12. The deflectable catheter shaft section 12 canbe configured for deflection independent of the proximal catheter shaftsection 20.

Referring now to FIG. 2A, deflectable catheter shaft section 12 extendsalong a longitudinal axis A and comprises at least five substantiallyseparate lumens 24, 26, 28, 30, 32, each extending along thelongitudinal axis A from the distal end 14 to the proximal end 16 inaccordance with an embodiment of the invention. Each of the plurality oflumens 24, 26, 28, 30, 32 can be fully formed in accordance with anembodiment of the invention. In particular, each of the plurality oflumens can be a desired shape as described hereinbelow. Depending uponthe intended application of the catheter 10, each lumen 24, 26, 28, 30,32 may extend along an entire length of the deflectable catheter shaftsection 12 or may extend less than the entire length of the deflectablecatheter shaft section 12. Each lumen 24, 26, 28, 30, 32 may be formedto have a predetermined cross-sectional profile and shape. Each lumen24, 26, 28, 30, 32 is configured such that various components requiredfor performing the particular functionality of the catheter 10 (e.g.,recording electrograms, ablation, ultrasound, etc.) are disposedtherein.

Referring now to FIGS. 2A and 2B, first lumen 24 may be generally roundin cross-sectional shape. Although this particular shape is mentioned indetail, the cross-sectional shape of the first lumen 24 may vary inaccordance with various embodiments of the invention. First lumen 24 maybe configured for housing wiring for electrodes as described in moredetail hereinbelow or for other electrical components.

Second lumen 26 may be located generally adjacent to or abutting thefirst lumen 24 within deflectable catheter shaft section 12. Inaccordance with an embodiment of the invention, the first and secondlumens 24, 26 may be disposed as proximate each other as manufacturallyfeasible, while allowing the first and second lumens 24, 26 to be fullyformed. For example and without limitation, the distance between firstlumen 24 and second lumen 26 may be less than about 0.015 inches (0.38mm) in accordance with an embodiment of the invention. In an embodiment,the first lumen 24 and the second lumen 26 may be connected to eachother. Second lumen 26 may be generally round in cross-sectional shape.Although this particular shape is mentioned in detail, thecross-sectional shape of the second lumen 26 may vary in accordance withvarious embodiments of the invention. Second lumen 26 may be configuredfor use as an irrigation fluid passageway and the like.

Third lumen 28 may be located generally adjacent to or abutting bothfirst and second lumens 24, 26. In accordance with an embodiment of theinvention, the third lumen 28 and the first and second lumens 24, 26 maybe disposed as proximate each other as manufacturally feasible, whileallowing the first, second, and third lumens 24, 26, 28 to be fullyformed. For example and without limitation, the distance between thirdlumen 28 and at least one of the first lumen 24 and second lumen 26 maybe less than about 0.015 inches (0.38 mm) in accordance with anembodiment of the invention. In an embodiment, the third lumen 28 and atleast one of the first lumen 24 and the second lumen 26 may be connectedto each other. Third lumen 28 may be generally rectangular incross-sectional shape. Although this particular shape is mentioned indetail, the cross-sectional shape of the third lumen 28 may vary inaccordance with various embodiments of the invention. Third lumen 28 maybe configured to house a planarity wire 34 (FIG. 2B). The planarity wire34 has opposing flat surfaces 36, 38 and is configured to maintain theplanarity of the deflectable catheter shaft section 12 as thedeflectable catheter shaft section 12 deflects.

Fourth and fifth lumens 30, 32 may be located on opposing sides of thethird lumen 28 for the planarity wire 34. The fourth lumen 30 may belocated generally adjacent to or abutting the third lumen 28. Inaccordance with an embodiment of the invention, the third and fourthlumen 28, 30 may be disposed as proximate each other as manufacturallyfeasible, while allowing the third and fourth lumens 28, 30 to be fullyformed. For example and without limitation, the distance between fourthlumen 30 and the third lumen 28 may be less than about 0.010 inches(0.254 mm). In an embodiment, the fourth lumen 30 and the third lumen 28may be connected to each other. The fifth lumen 32 may be locatedgenerally adjacent to or abutting the second lumen 26. In accordancewith an embodiment of the invention, the second and fifth lumens 26, 32may be disposed as proximate each other as manufacturally feasible,while allowing the second and fifth lumens 26, 32 to be fully formed.For example and without limitation, the distance between the fifth lumen32 and the second lumen 26 may be less than about 0.010 inches (0.254mm). In an embodiment, the fifth lumen 32 and the second lumen 26 may beconnected to each other. The fourth and fifth lumens 30, 32 may begenerally round in cross-sectional shape. Although these particularshapes are mentioned in detail, the cross-sectional shape of the fourthand fifth lumens 30, 32 may vary in accordance with various embodimentsof the invention. Fourth and fifth lumens 30, 32 may be configured toeach house a pull wire 40, 42 (FIG. 2B) to enable the deflectablecatheter shaft section 12 to deflect in two or more directions. Inparticular, the handle assembly 22 described in more detail hereinbelowmay comprise at least one pull wire 40, 42 operatively connected to itto facilitate deflection of the deflectable catheter shaft section 12.Although the deflectable catheter shaft section 12 is described andillustrated as including two opposing pull wires 40, 42, it should benoted that the deflectable catheter shaft section 12 of catheter 10 isnot limited to two opposing pull wires 40, 42. Rather, the deflectablecatheter shaft section 12 of catheter 10 may include a single pull wirearrangement in other embodiments of the invention. The deflectablecatheter shaft section 12 of catheter 10 may include more than two pullwires in other embodiments of the invention. The pull wires 40, 42 maybe formed from a superelastic nickel-titanium (known as NiTi or Nitinol)wire, carbon fiber, para-aramid synthetic fiber generally available fromDuPont under the brand name KEVLAR®, or other suitable material inaccordance with various embodiments of the invention.

Still referring to FIG. 2B, each of the lumens 24, 26, 28, 30, 32 may belined with liners 44 that serve the purpose of providing a lubricioussurface (e.g., to allow for the sliding of the pull wires) andinsulating the components within the lumens 24, 26, 28, 30, 32. Ifprovided, the liners 44 may be constructed of a polymeric material, suchas PTFE or any other suitable material.

Referring now to FIG. 3, deflectable catheter shaft section 12 comprisesa first pocket 46 at distal end 14 configured to accept a pull ring 48(FIG. 4A). Pull wires 40, 42 are attached to diametrically oppositelocations on the pull ring 48 by a solder or weld joint, for example andwithout limitation. The pull wires 40, 42 then extend from the pull ring48 toward the handle assembly 22. Pulling of the pull wires 40, 42 bythe handle assembly 22 during use of the catheter 10 will cause the pullring 48 to tilt or rock, thereby deflecting the deflectable cathetershaft section 12. The first pocket 46 at distal end 14 is alsoconfigured to accept tip assembly 18.

Referring back to FIG. 1, tip assembly 18 comprises a tip electrode 56having a distal end 50 and a proximal end 52. Tip electrode 56 may beconfigured for various functions and may include, without limitation, anactive outer surface that is configured for exposure to blood and/ortissue. The tip electrode 56 may be affixed to distal end 14 of thedeflectable catheter shaft section 12 in a number of ways. For instance,the tip electrode 56 may be bonded to an inner radial surface of thedeflectable catheter shaft section 12 using an epoxy material. As usedherein, the term “radial surface” means a surface at a radial distancefrom a central axis or a surface developing uniformly around a centralaxis (for example, but without limitation, an arcuate surface, anannular surface, or a cylindrical surface). The tip electrode 56 of thetip assembly 18 may have an aperture (not shown) formed therein that issufficiently sized and configured to receive a wire (not shown) that isconnected to the tip electrode 56. One end of the wire is connected tothe tip electrode 56 and the other end is connected to, for example,monitoring or recording or ablation devices, such as a radiofrequency(RF) generator. The wire is typically a pre-coated wire that isinsulated from other components in the tip assembly 18. The tipelectrode 56 of the tip assembly 18 may further include an aperture (notshown) formed therein that is configured to receive a thermocouple (notshown). The thermocouple may be configured to measure the temperature ofthe tip electrode 56, targeted tissue, and/or the interface therebetweenand provide feedback to the monitoring or recording or ablation devicesdescribed hereinabove. The tip electrode 56 may further include a fluidlumen configured as a passageway for irrigation fluid.

Referring back to FIG. 3, deflectable catheter shaft section 12comprises a second pocket 58 at proximal end 16 configured to accept ashaft coupler 60 (FIGS. 4A-4B). Referring to FIGS. 4A-4B, the shaftcoupler 60 is configured to connect the deflectable catheter shaftsection 12 to the proximal catheter shaft section 20. A distal end 62 ofthe shaft coupler 60 can be affixed to the proximal end 16 of thedeflectable catheter shaft section 12 in a number of ways. For instance,an outer radial surface 64 of the shaft coupler 60 may be bonded to aninner radial surface 66 of the deflectable catheter shaft section 12using an epoxy material, for example and without limitation. A proximalend 68 of the shaft coupler 60 can be affixed to a distal end 70(FIG. 1) of the proximal catheter shaft section 20 in a number of ways.For instance, the outer radial surface 64 of the shaft coupler 60 may bebonded to an inner radial surface (not shown) of the proximal cathetershaft section 20 using an epoxy material, for example and withoutlimitation. The outer radial surface 64 of the shaft coupler 60 cancomprise a helical groove 71 in accordance with some embodiments of theinvention. The helical groove 71 can be configured to have a variabledepth in accordance with various embodiments of the invention. Thehelical groove 71 can be configured to improve bonding between the shaftcoupler 60 and the deflectable catheter shaft section 12 in accordancewith various embodiments of the invention. For example, in at least oneembodiment the groove 71 may be configured to hold an adhesive addedduring manufacturing of the catheter 10. In another embodiment, thegroove 71 may be configured to bond and/or grab onto various portions ofthe shaft sections 12 and 20 during a reflow process, described in moredetail below. In another embodiment, the helical groove 71 may beconfigured both to hold an adhesive and bond/grab onto the shaftsections 12 and 20 during a reflow process. The shaft coupler 60 can begenerally cylindrical in shape. The shaft coupler 60 can also include aplurality of lumens 72, 74, 76, 78, 80 in communication with lumens 24,26, 28, 30, 32 of deflectable catheter shaft section 12, which functionas an electrical lumen, fluid lumen, planarity wire lumen, and pull wirelumens, respectively.

Referring now to FIG. 5, deflectable catheter shaft section 12 can beconstructed of a series of polymer layer(s) and braid structure(s). Inparticular, one or more wires wound to form a cylindrical braidstructure can substantially surround the plurality of lumens 24, 26, 28,30, 32. In addition, a polymeric material, such as polyurethane, nylon,or various types of plastic materials such as polyether block amidesoffered under the trademark PEBAX®, which is a registered trademark ofArkema France, Puteaux, France, or any other suitable material, can alsosubstantially surround the plurality of lumens 24, 26, 28, 30, 32.Regardless of the material used, the material must have the capabilityto be displaced or to shrink when subjected to a process, such as forexample, a heating process that is performed.

The deflectable catheter shaft section 12 can include one or moreelectrodes (such as, for example, ring electrodes 54) mounted on oraffixed to the deflectable catheter shaft section 12. In theseparticular embodiments, an active outer surface of each electrode 54 canbe configured for exposure to blood and/or tissue. Each electrode 54 maybe assembled with the deflectable catheter shaft section 12 using anynumber of known processes. For instance, the electrodes 54 may be builtinto the deflectable catheter shaft section 12 using a reflow process.In such a process, the electrodes 54 are placed at theappropriate/desired locations on the deflectable catheter shaft section12, and then the tip deflectable catheter shaft section 12 is exposed toa heating process in which the electrodes 54 and polymeric materialforming the deflectable catheter shaft section 12 become affixed orbonded together. Sufficiently sized aperture(s) are formed in thedeflectable catheter shaft section 12 proximate to each electrode 54 inorder to allow for wires (not shown) connected to the electrodes 54 tobe threaded into first lumen 24 of deflectable catheter shaft section12, for example, which may be configured for housing wiring forelectrodes. The wires may extend through the lumen 24 of deflectablecatheter shaft section 12 and may be connected to, for example,monitoring and/or recording devices and/or ablation devices associatedwith or connected to the catheter 10. These devices are typicallylocated proximate to the handle assembly 22. The wires are typicallypre-coated wires such that they are insulated from each other and othercomponents in the catheter 10.

The mechanical properties of the deflectable catheter shaft section 12can be varied by varying the properties of the cylindrical braidstructure(s) and the polymeric material (e.g., dimension of thecylindrical braid structure and/or durometers of the polymers).Additionally, the mechanical properties of the deflectable cathetershaft section 12 can be varied along the length of the deflectablecatheter shaft section 12 in accordance with some embodiments of thedisclosure or can be substantially constant along the entire length ofthe deflectable catheter shaft section 12 in accordance with otherembodiments of the disclosure.

Referring again to FIG. 1, proximal catheter shaft section 20 can alsoinclude one or more lumens (not shown). Generally, proximal cathetershaft section 20 can include a single lumen. The single lumen can be incommunication with lumens 72, 74, 76, 78, 80 of shaft coupler 60, whichare in turn in communication with lumens 24, 26, 28, 30, 32 ofdeflectable catheter shaft section 12. Proximal catheter shaft section20 can also be constructed of a series of polymer layer(s) and braidstructure(s). In particular, one or more wires wound to form acylindrical braid structure can substantially surround the one or morelumens of proximal catheter shaft section 20. In addition, a polymericmaterial, such as polyurethane, nylon, or various types of plasticmaterials such as polyether block amides offered under the trademarkPEBAX®, or any other suitable material, can also substantially surroundthe one or more lumens of proximal catheter shaft section 20. Regardlessof the material used, the material must have capability to be displacedor to shrink when subjected to a process, such as for example, a heatingprocess that is performed. The mechanical properties of the proximalcatheter shaft section 20 can also be varied by varying the propertiesof the cylindrical braid structure(s) and the polymeric material (e.g.,dimension of the cylindrical braid structure and/or durometers of thepolymers). Additionally, the mechanical properties of the proximalcatheter shaft section 20 can be varied along the length of the proximalcatheter shaft section 20 in accordance with some embodiments of thedisclosure or can be substantially constant along the entire length ofthe proximal catheter shaft section 20 in accordance with otherembodiments of the disclosure.

Referring now to FIGS. 6-8, the catheter 10 can include first and secondtightly wound compression coils 82, 84 disposed in the proximal cathetershaft section 20 before engaging with the lumens 78, 80 of shaft coupler60, which are in turn in communication with fourth and fifth lumens 30,32, which extend through the deflectable catheter section 12. Each ofthe compression coils 82, 84 can comprise stainless steel in accordancewith an embodiment of the invention. Each of the compression coils 82,84 comprises a distal end 86 and a proximal end 88 (see FIG. 8). Theouter diameter of the compression coils 82, 84 can be about 0.015 inches(0.38 mm) to about 0.030 inches (0.76 mm). The inner diameter of thecompression coils 82, 84 can be about 0.004 inches (0.10 mm) to about0.015 inches (0.38 mm). The compression coils 82, 84 are disposed overpull wires 40, 42. The pull wires 40, 42 extend from the pull ring 48(FIG. 4A), through the deflectable catheter shaft section 12, throughthe shaft coupler 60, through the proximal catheter shaft section 20 tothe handle assembly 22, but the compression coils 82, 84 generallyextend only through the proximal catheter shaft section 20. Thecompression coils 82, 84 can extend the entire length of the proximalcatheter shaft section 20 in accordance with some embodiments of theinvention. In some embodiments, the one or more lumens of the proximalcatheter shaft section 20 can be lined with liners (not shown) thatserve the purpose of providing a lubricious surface (e.g., to allow forthe sliding of the pull wires 40, 42). If provided, the liners may beconstructed of a polymeric material, such as PTFE, or any other suitablematerial.

In order to provide the desired mechanical property of resistingcompression during use, a catheter may incorporate a stainless steelcompression coil embedded within an outer layer of the catheter shaft.However, in accordance with an embodiment of the present invention, thedistal end 86 of each of the compression coils 82, 84 may not beembedded within an outer layer of the catheter shaft and may nototherwise be fixedly attached to the catheter 10 or components thereof.Instead, the compression coils 82, 84 may comprise floating members thatare “sandwiched” in between components located at the distal end 86 andproximal end 88 of each of the compression coils 82, 84. By separatingthe compression coils 82, 84 from the catheter shaft itself, thecatheter 10 can undergo bench testing for assessing deflection of thecatheter 10 prior to formation of the catheter shaft through a reflowprocess as described in more detail hereinbelow. Moreover, by notfixedly attaching the compression coils 82, 84 to the catheter 10 orcomponents thereof, the invention may exhibit improved ease of assembly.The distal end 86 of each compression coil 82, 84 can abut or beconstrained by the proximal end 68 of the shaft coupler 60 as generallyillustrated in FIGS. 6 and 7. As generally illustrated, the distal end86 of each of the compression coils 82, 84 is not fixedly attached tothe shaft coupler 60, but instead abuts or stops at or is constrained byan axial end surface of the shaft coupler 60 (as best shown in FIG. 7).Referring now to FIG. 8, the proximal end 88 of each compression coil82, 84 can abut a distal end 90 of a portion of the handle assembly 22.Again, the proximal end 88 of each of the compression coils 82, 84 isnot fixedly attached to the handle assembly 22, but instead abuts orstops at or is constrained by an axial end surface of the distal end 90of a portion of the handle assembly 22. Each compression coil 82, 84 istightly wound so it can bend, but is non-compressible.

Because the compression coils 82, 84 are non-compressible, tension onthe pull wires 40, 42 will not translate into compressive tension on theproximal catheter shaft section 20. The compression coils 82, 84 aretherefore configured to help assure that the proximal catheter shaftsection 20 does not bend as a result of tension on the pull wires 40, 42and that rotational control of the catheter 10 is not adversely affectedwhen the pull wires 40, 42 are under tension. By separating thecompression coils 82, 84 from the outer wall of the proximal cathetershaft section 20, the proximal catheter shaft section 20 is configuredto provide pushability and torqueability for the catheter 10, withoutconcomitant shaft compression and/or snaking.

Referring back to FIG. 1, the handle assembly 22 is coupled to theproximal catheter shaft section 20 at its proximal end (disposed withinhandle assembly 22 and not shown). The handle assembly 22 is operativeto, among other things, effect movement (i.e., deflection) of thedeflectable catheter shaft section 12. The handle assembly 22 includes adistal end 94 and a proximal end 96. Referring now to FIGS. 9A and 9Band as will be described in greater detail below, the handle assembly 22includes an actuator 98 that can be selectively manipulated to causedeflectable catheter shaft section 12 to deflect in one or moredirections (e.g., up, down, left, and right). Deflectable catheter shaftsection 12 may be configured for uni-directional deflection inaccordance with some embodiments of the invention and may be configuredfor bi-directional deflection in accordance with other embodiments ofthe invention.

Still referring to FIGS. 9A and 9B, the handle assembly 22 includes anactuator 98, an upper grip portion 101 (see FIG. 1) and a lower gripportions 100, an electrical plug 102 at the proximal end 96 of thehandle assembly 22, and a strain relief 104 at the distal end 94 of thehandle assembly 22. The upper and lower grip portions 101, 100, whenassembled, define a space 106 that extends laterally through the gripportions 101, 100. The actuator 98 is pivotally coupled to the gripportions 100 and resides in the space 106. The actuator 98 may pivotallydisplace laterally relative to the grip portions 100 through the space106. Such pivotal displacement of the actuator 98 allows medicalpersonnel to bi-directionally deflect the deflectable catheter shaftsection 12. The pull wires 40, 42 extend from the pull ring 48 (see FIG.4A), through the deflectable catheter shaft section 12, through theshaft coupler 60, through the proximal catheter shaft section 20, andinto the handle assembly 22 to couple to an actuation mechanism 108 ofthe actuator 98 as will be described in more detail hereinbelow. Theupper and lower grip portions 101, 100 are adapted to matingly couplewith each other and serve as an enclosure and mounting base for theactuation mechanism 108 mounted in a distal portion of the handleassembly 22. The electrical plug 102 is adapted to be connected to amonitoring or a recording or an ablation device. The electrical plug 102is mounted in a proximal end assembly that serves as the proximal end 96of the handle assembly 22. The structure and function of the actuationmechanism 108 and the actuator 98 is described in detail in U.S. Pat.No. 7,465,288, which is hereby incorporated by reference as though setforth in its entirety.

The catheter 10 may include any number of other elements such as, forexample and without limitation, thermocouples, thermistor temperaturesensors, etc. for monitoring the temperature of targeted tissue andcontrolling the temperature.

With reference to FIGS. 10A-15, a method of manufacturing thedeflectable catheter shaft section 12 will now be described. Theexemplary method comprises a first step of providing a fluid lumenmandrel 110 (FIGS. 10A and 10B), an electrical lumen mandrel 112 (FIGS.10B and 10C), a planarity wire mandrel 114 (FIG. 10A), and two pull wiremandrels 116, 118 (FIGS. 10A-10C). The exemplary method furthercomprises a second step of providing a mandrel alignment tool 120.

Referring in particular to FIG. 11, the mandrel alignment tool 120comprises a plurality of slots 122, 124, 126, 128, 130 eachcorresponding to one of the fluid lumen mandrel 110, the electricallumen mandrel 112, the planarity wire mandrel 114, and the two pull wiremandrels 116, 118, respectively. The mandrel alignment tool 120 can beformed by wire cutting from slot to slot in an exemplary method ofmanufacturing the catheter 10. The exemplary method further comprises athird step of placing polymeric tubes (e.g., polymeric tubes 132, 134,136 as generally illustrated in FIG. 12) over each of the mandrels 110,112, 114, 116, 118 so that the polymeric tubes externally surround eachof the mandrels 110, 112, 114, 116, 118. Although FIG. 12 only showspolymeric tubes over mandrels 110, 114, and 116, those of ordinary skillin the art will recognize that polymeric tubes are disposed over each ofthe mandrels. The polymeric tubes (e.g., polymeric tubes 132, 134, 136)can comprise PTFE in accordance with an embodiment of the invention.

Referring now to FIGS. 13-15 in particular, the exemplary methodcomprises a fourth step of providing tooling 138 configured to hold themandrel alignment tool 120. In an exemplary embodiment, the tooling 138comprises five pairs of opposing clamps or tensioning blocks 140 a, 140b; 142 a, 142 b; 144 a, 144 b; 146 a, 146 b; and 148 a, 148 b. Each pairof opposing clamps or tensioning blocks 140 a, 140 b; 142 a, 142 b; 144a, 144 b; 146 a, 146 b; and 148 a, 148 b corresponds to one of themandrels 110, 112, 114, 116, 118, and the mandrel alignment tool 120respectively. The opposing clamps or tensioning blocks 140 a, 140 b; 142a, 142 b; 144 a, 144 b; 146 a, 146 b; and 148 a, 148 b are disposed atopposite ends of at least one elongate member 150. The elongate member150 is configured for facilitating placement of the clamps or tensioningblocks 140 a, 140 b; 142 a, 142 b; 144 a, 144 b; 146 a, 146 b; and 148a, 148 b in a predetermined, select position relative to each other. Afirst set of clamps or tensioning blocks 140 a, 142 a, 144 a, 146 a, 148a are in a fixed position and are generally illustrated in FIG. 14. Asecond set of clamps or tensioning blocks 140 b, 142 b, 144 b, 146 b,148 b are configured for tensioning. This second set of clamps ortensioning blocks 140 b, 142, 144 b, 146 b, 148 b are configured toallow each mandrel 110, 112, 114, 116, 118 to be placed under tensionand then released from tension as desired. The tooling 138 can furthercomprise a compression block 152 at one end of the elongate member 150.The compression block 152 can be disposed on the elongate member 150near the second set of clamps or tensioning blocks 140 b, 142 b, 144 b,146 b, 148 b.

The exemplary method further comprises a fifth step of clamping mandrels110, 112, 114, 116, 118 and the surrounding polymeric tubes into placeon the tooling 138. In particular, the mandrel alignment tool 120 may beplaced at both ends of the tooling 138 to facilitate proper placement oralignment of the mandrels 110, 112, 114, 116, 118 in the tooling 138.The mandrels 110, 112, 114, 116, 118 may be placed within slots locatedwithin each of the opposing clamps or tensioning blocks 140 a, 140 b;142 a, 142 b; 144 a, 144 b; 146 a, 146 b; and 148 a, 148 b and eachmandrel 110, 112, 114, 116, 118 may be clamped in place into one pair ofthe opposing clamps or tensioning blocks 140 a, 140 b; 142 a, 142 b; 144a, 144 b; 146 a, 146 b; and 148 a, 148 b.

The exemplary method further comprises a sixth step of tensioning eachmandrel 110, 112, 114, 116, 118 (e.g., through use of tension block 152)and a seventh step of releasing tension of each mandrel 110, 112, 114,116, 118 (e.g., through release of tension block 152). The exemplarymethod further comprises an eighth step of placing (e.g., sliding) thecylindrical braid structure described hereinabove over the group ofmandrels 110, 112, 114, 116, 118 and corresponding surrounding polymeric(e.g., PTFE) tubes and stretching the cylindrical braid structure tightover the group of mandrels 110, 112, 114, 116, 118 and correspondingsurrounding polymeric tubes.

The exemplary method further comprises the ninth step of placing (e.g.,sliding) one or more polymeric tubes over the cylindrical braidstructure. The one or more polymeric tubes slid over the cylindricalbraid structure can comprise polyurethane, nylon, or various types ofplastic materials such as polyether block amides offered under thetrademark PEBAX®, or any other suitable material, in accordance withvarious embodiments of the invention. The mechanical properties of thedeflectable catheter shaft section 12 can be varied by varying theproperties the polymeric materials (e.g., durometers of the polymericmaterials utilized).

The exemplary method further comprises the tenth step of placing (e.g.,sliding) a heat shrink tube (not shown) over the one or more polymerictubes such that both ends of the heat shrink tube are covering themandrel alignment tools 120 at both ends of the tooling 138. Theexemplary method comprises the eleventh step of pre-shrinking the heatshrink tube. The step of pre-shrinking the heat shrink tube can beaccomplished with a heat gun or other heat source in accordance withvarious embodiments of the invention. The exemplary method furthercomprises the twelfth step of placing the tooling 138 and accompanyingmandrels 110, 112, 114, 116, 118, polymeric (e.g., PTFE) tubes,cylindrical braid structure, polymeric (e.g., polyurethane, nylon,polyether block amides available under the brand name PEBAX®) tubes, andheat shrink tubing into an oven or other heat source and subjecting themto a heating process that includes reflowing a portion of thedeflectable catheter shaft section 12. The temperature of the oven andthe length of the time for the heating process can vary in accordancewith various embodiments of the invention. The exemplary method furthercomprises the thirteenth step of removing the mandrels 110, 112, 114,116, 118 and heat shrink tubing in accordance with methods known bythose of ordinary skill in the art. The exemplary method furthercomprises the fourteenth step of trimming the deflectable catheter shaftsection 12 to a predetermined, select length.

The exemplary method can further comprise additional steps of insertingone or more components into one or more lumens in the deflectablecatheter shaft section 12 that were formed. In an exemplary embodiment,the components inserted and disposed within the lumens can include, asdescribed above, at least one electrode wire, a planarity wire 34,and/or at least one pull wire 40, 42. The components within thedeflectable catheter shaft section 12 can take the form of any number ofdifferent or additional articles/devices typically present in cathetersused for diagnostic or therapeutic purposes (e.g., wires correspondingto temperature sensing elements, etc.).

FIG. 16 is an isometric view of an alternative to the shaft coupler 60shown to good advantage in FIGS. 4A, 4B, and 7. In this embodiment, theshaft coupler 60′ comprises a plurality of circumferentially-extendingridges 154 separated by a plurality of circumferentially-extendingrecesses or grooves 156. As may also be seen to good advantage in FIG.16, the alternative shaft coupler 60′ may include one or morelongitudinally-extending troughs 158. Since these shaft couplers, inaddition to carrying components as will be described in more detailbelow, are used to join abutting catheter shaft sections (e.g., 12 and20), the plurality of ridges 154, recesses 156, and troughs 158 helpensure a secure connection between catheter shaft sections. The recessesand troughs may, for example, provide a place for adhesive that is usedto attach catheter shaft sections to take purchase on the shaft coupler60′. The ridges 154, including the circumferentially-extending edges 160of each ridge, and the edges 162 of each longitudinally-extending trough158, help prevent both undesired rotation of the shaft coupler relativeto the catheter shaft sections, as well as undesirable longitudinalseparation of adjacent catheter shaft sections.

As is also shown to good advantage in FIG. 16, this shaft couplerembodiment 60′ includes a plurality of longitudinally-extending lumens24′, 26′, 30′, 32′. In particular, there are two diametrically-opposedpull wire lumens, including a first pull wire 30′ lumen and a secondpull wire lumen 32′. There are also two diametrically-opposed largerlumens, including a first larger lumen 24′ and a second larger lumen26′. In this configuration of the shaft coupler 60′, as shown in FIG.16, the first pull wire lumen 30′ and the second pull wire lumen 32′ aresymmetrically disposed above and below, respectively, an imaginary,longitudinally-extending horizontal plane (not shown) bisecting theshaft coupler into an upper hemicylindrical portion and a lowerhemicylindrical portion. Similarly, the first larger lumen 24′ and thesecond larger lumen 26′ are also symmetrically disposed relative to animaginary, longitudinally-extending vertical plane (not shown) bisectingthe shaft coupler into a left hemicylindrical portion and a righthemicylindrical portion as oriented in FIG. 16. Each of the four lumens24′, 26′, 30′, 32′ depicted in FIG. 16 may be lined (see, for example,the liners 44 in FIG. 2B).

FIG. 16A depicts another alternative shaft coupler 60″, which is mostsimilar to the shaft coupler 60′ depicted in FIG. 16, but with a singlelarger lumen 27. It should also be noted that the outer radial surfaceof the shaft couplers depicted in FIGS. 16 and 16A could have a helicalgroove cut in it, like the helical groove 71 cut in the outer surface ofthe shaft coupler 60, as shown in FIG. 4B. Similarly, the shaft coupler60 shown in FIG. 4B could have its exterior surface configured like theexterior surface of the shaft couplers 60′ and 60″depicted in FIGS. 16and 16A, respectively.

FIGS. 17 and 18 depict a deflectable catheter shaft section 12′ similarto the deflectable catheter shaft section 12 shown to good advantage in,for example, FIGS. 1, 3, and 4A. As shown in FIGS. 17 and 18, thecatheter shaft may include the deflectable catheter shaft section 12′,an intermediate catheter shaft section 164, and a proximal cathetershaft section (not shown in FIGS. 17 and 18, but the proximal cathetershaft section, if present, would abut the right longitudinal end, asoriented in FIGS. 17 and 18, of the intermediate catheter shaft section164). In this embodiment, two shaft couplers are used, including aproximal shaft coupler 60 _(P) for coupling the proximal catheter shaftsection to the intermediate catheter shaft section 164, and a distalshaft coupler 60 _(D) for coupling the intermediate catheter shaftsection 164 to the deflectable catheter shaft section 12′. The proximalshaft coupler 60 _(P) and the distal shaft coupler 60 _(D) may be, forexample, shaft couplers with the configuration of shaft coupler 60 (seeFIGS. 4A, 4B, and 7), shaft coupler 60′ (see FIG. 16), shaft coupler 60″(see FIG. 16A), or a combination of these or other shaft couplers. Forexample, in one embodiment, the proximal shaft coupler 60 _(P) may bethe configuration of shaft coupler 60″ (see FIG. 16A) and the distalshaft coupler 60 _(D) may be the configuration of shaft coupler 60′ (seeFIG. 16). In another exemplary embodiment, the distal shaft coupler 60_(D) and the proximal shaft coupler 60 _(P) may both be theconfiguration of shaft coupler 60′ (see FIG. 16).

In at least one embodiment, the proximal catheter shaft section maycomprise a portion of the handle assembly, e.g., the proximal cathetershaft section may comprise a pocket (not shown) sized and configured toreceive a proximal shaft coupler 60 _(P) and formed in the distal end 94of handle assembly 22 seen in FIG. 9B. In an alternative embodiment, itis possible, depending upon which handle assembly 22 is selected, thatthe handle assembly may connect to the proximal end 168 of theintermediate catheter section 164, or to the proximal end 166 of theproximal shaft coupler 60 _(P). In these latter configurations, theintermediate catheter shaft section 164 would be analogous to theproximal catheter section shown in, for example, FIG. 1.

Referring more particularly to FIG. 18, additional details will bedescribed. FIG. 18 is a cross-sectional view taken along line 18-18 ofFIG. 17. Starting from the right side of FIG. 18 and moving leftward, aproximal end 166 of the proximal shaft coupler 60 _(P) may be seenextending proximally beyond the proximal end 168 of the intermediatecatheter shaft section. It is also possible to see that the intermediatecatheter shaft section 164 may include a first shaft material 170 (e.g.,PEBAX) and a second shaft material 172 (e.g., PEBAX or braided mesh). Afirst pull wire 40 may be seen extending along the upper portion of theproximal shaft coupler 60 _(P), and a second pull 42 wire may be seenextending adjacent a lower portion of the proximal shaft coupler 60_(P). The portion of these pull wires 40, 42 extending from the proximalend 166 of the proximal shaft coupler 60 _(P) back to the handleassembly 22 (see, for example, FIG. 1) may have compression coils, suchas tightly-wound compression coils 82, 84 (shown to good advantage inFIGS. 6 and 7), surrounding them. Additionally, there may be compressioncoils (not shown) extending between a distal end 174 of the proximalshaft coupler 60 _(P) and a proximal end 176 of the distal shaft coupler60 _(D). These compression coils would be under compression (e.g., theymay be compressed 0.070 in.) to help mitigate against undesirabledeformation of the intermediate catheter shaft section 164 extendingbetween the proximal and distal shaft couplers. In the embodiment shown,the compression coils do not extend through the proximal shaft coupler,but they could in an alternative embodiment.

Moving further leftward in FIG. 18, you next encounter the distal shaftcoupler 60 _(D), which is depicted as joining the intermediate cathetershaft section 164 (which, as discussed above, may extend to the handleassembly 22) to the deflectable catheter shaft section 12′ that extendsfrom the distal shaft coupler to the assembly tip 18′. As may be seenfrom FIG. 18, in this embodiment, both the proximal shaft coupler 60_(P) and the distal shaft coupler 60 _(D) are constructed according tothe shaft coupler embodiment depicted in, for example, FIG. 16, butthese couplers could be constructed differently and could be differentfrom each other. A distal end 178 of the distal shaft coupler 60 _(D)may be seen to better advantage in FIG. 21, which is an enlarged view ofthe portion of the catheter within dashed circle AA of FIG. 18. Sinceboth FIGS. 18 and 21 are longitudinally-extending, cross-sectionalviews, it is possible to see a vertical web 180 (i.e., a line of shaftcoupler material) located between the larger lumen 24′, 26′ andextending vertically between the first pull wire lumen 30′, and thesecond pull wire lumen 32′. You may also see a portion of the samecoupler material above the first pull wire lumen 30′ and below thesecond pull wire lumen 32′. As shown in FIGS. 18 and 21, when the firstpull wire 40 exits the distal end 178 of the distal shaft coupler 60_(D), it enters a liner 182 (e.g., a thin-walled PTFE tube). The secondpull wire 42, upon exiting the distal end 178 of the distal shaftcoupler 60 _(D), extends through a bendable stiffening member (e.g., a‘coil pack’ or a ‘spring pack’ or an ‘uncompacted spring pack’ or a‘deflection facilitator’) 184, the proximal end of which is visible inFIG. 18. The construction of the bendable stiffening member 184 in thedeflectable catheter shaft section 12′ will be described in more detailbelow with reference to, for example, FIGS. 21 and 23-28.

As shown to good advantage in dashed circle CC depicted in both FIGS. 18and 20, the first and second pull wires 40, 42 are attached todiametrically opposed locations on the pull ring 48′. Distal to the pullring 48′ in the configuration depicted in FIGS. 17 and 18 are aplurality of ring electrodes 54 followed distally by a tip assembly 18′,including, for example, a flexible tip electrode from a Therapy™ CoolFlex™ ablation catheter manufactured by St. Jude Medical, Inc. of St.Paul, Minn. Additional details regarding a flexible electrode tip may befound in, for example, U.S. Pat. No. 8,187,267 B2 and United Statespatent application publication no. US 2010/0152731 A1, each of which ishereby incorporated by reference as though fully set forth herein. Thetip assembly 18′, as depicted in FIG. 18, also includes a barbedconnector 185 that locks into a complementary pocket 187, therebyfacilitating delivery of irrigant to a ported fluid distribution tube189. FIG. 19 is an end view of the tip assembly 18′ (looking in thedirection of the arrows on line 19-19 of FIG. 18) and illustrates aplurality of irrigation ports 190 through the distal surface of the tip.

As may be seen in FIGS. 21 and 23, the bendable stiffening member 184includes, in this embodiment, a multi-pitch coil 186 (see FIG. 24 for anisometric view of the multi-pitch coil) that is partially covered by acoil support tube 188. This coil support tube may be, for example, apolyimide tube or a NiTi tube or a tube constructed from some otherflexible material capable of bending with and supporting the internalcoil 186 comprising part of the bendable stiffening member. As alsoshown to good advantage in FIG. 21, when the second pull wire 42 exitsthe distal end of the bendable stiffening member 184, it enters a liner182 (e.g., a thin-walled PTFE tube). The first and second pull wires 40,42 then continue distally to a pull ring 48′.

FIG. 22 is an enlarged, fragmentary, isometric view of the distal end176 of the distal shaft coupler 60 _(D), which is depicted in thisfigure as having the configuration of the shaft coupler 60′. In thefigure, the outer shaft material has been removed for clarity. As shownin FIG. 22, the proximal portion of the distal shaft coupler 60 _(D) ismounted in the intermediate catheter shaft section 164 and is shownextending from the distal end 192 of the intermediate catheter shaftsection 164. The first pull wire lumen 30′ has a first pull wire 40extending from it, and that first pull wire is covered by a liner 182.The second pull wire 42 is shown extending distally from the second pullwire lumen 32′. The second pull wire is depicted surrounded by abendable stiffening member, such as the bendable stiffening member 184depicted in FIG. 23. In FIG. 22, however, only the proximal portion ofthe bendable stiffening member 184 is shown. In particular, in FIG. 22,a proximal, spaced-coil portion 194 of a multi-pitch coil 186 is shown,as is a proximal portion of the coil support tube 188. Additionally, aportion of one coil 202 of a stacked-coil portion 196 of the multi-pitchcoil 186 may also be seen in FIG. 22.

Referring now most particularly to FIGS. 23-28, further details of apossible construction for the bendable stiffening member 184 areprovided. FIG. 23 is an isometric view of the bendable stiffening member184. In this embodiment, a multi-pitch coil 186 is mounted within abendable coil support tube 188. FIG. 24 depicts one type of multi-pitchcoil 186 that could be assembled in the coil support tube 188. Themulti-pitch coil 186 depicted in FIG. 24 includes two spaced-coilportions 194, two stacked-coil portions 196, and a centrally-located,spread-coil portion 198 (see also FIG. 26). In one embodiment, eachspaced-coil portion 194 comprises a plurality (e.g., six) of slightlyseparated, individual coils 200; and each stacked-coil portion 196comprises a plurality (e.g., thirty-two) of touching, individual coils202; and the centrally-located, spread-coil portion 198 comprises aplurality (e.g., two) of slightly separated, individual coils 204.Referring back to FIG. 23, it possible to see that the two spaced-coilportions 194 extend from the longitudinal ends of the coil support tube188 in this embodiment. An additional advantage of this configuration isthat the gaps between coils 200 permit entry of a melt-processablematerial into these gaps when the catheter is manufactured (e.g., duringa reflow process), which can help to hold the bendable stiffening member184 in place in the assembled catheter.

In the particular embodiment shown in FIGS. 23-28, the multi-pitch coil186 is 0.74 inches long, each of the two stacked-coil portions 196 is0.1 inches long, and the spread-coil portion 198 is 0.018 inches long.Further, in this embodiment, each spaced-coil portion 194 comprises sixcoils (0.016666 pitch), and the central, spread-coil portion comprisestwo coils and 0.001 gaps 206 (0.009 pitch). In an alternativeembodiment, two spaced-coil portions may be separated by a single,centrally-located stacked-coil portion. In other alternativeembodiments, a single pitch coil could be used, for example, a tightlywound coil having no gaps between any coils from end-to-end, or a coilhaving the same size gap (e.g., a 0.001 gap) between all coils.

FIGS. 25, 26, and 27, are top, front, and end views, respectively, ofthe multi-pitch coil 186 depicted also depicted in FIG. 24. Although avariety of coil wire dimensions may be used effectively, a coil formedwith an inner diameter 208 (shown in, for example, FIG. 27) of 0.011inches, a wire thickness 210 (see FIG. 28) of 0.005 inches, and a wirewidth 212 (see FIG. 28) of 0.008 inches has been found to workeffectively with an appropriately-sized pull wire 40, 42. Coils havingan inner diameter of 0.014 inches, a wire thickness of 0.003 inches, anda wire width of 0.008 inches; or an inner diameter of 0.014 inches, awire thickness of 0.005 inches, and a wire width of 0.008 inches havealso been found to work effectively with an appropriately-sized pullwire. By varying, for example, the location and the size of the gapsbetween adjacent coils, the dimensions of the wire used to form thecoils, the size of the coils (e.g., ID and OD), the thickness of thecoil support tube, the material from which the coil support tube isconstructed, the length of the coil support tube relative to the lengthof the coil, and how tightly the coil support tube fits over the outerdiameter of the coil, it is possible to adjust and customize the bendingstiffness, the bending moment, and the bending radius of the resultingshape of the deflected catheter shaft distal portion. It should also benoted that the bendable stiffening member 184 does not carry acompression load like the compression load carried by compression coils82, 84, which are shown to good advantage in, for example, FIGS. 6 and7. It should also be noted that the bendable stiffening member 184 couldcomprise a single component (e.g., a flexible tube not requiring aninternal spring).

Although at least one embodiment of a deflectable catheter shaftsection, a catheter incorporating such a deflectable catheter shaftsection, and a method of manufacturing such a deflectable catheter shaftsection have been described above with a certain degree ofparticularity, those skilled in the art could make numerous alterationsto the disclosed embodiments without departing from the spirit or scopeof this disclosure. All directional references (e.g., upper, lower,upward, downward, left, right, leftward, rightward, top, bottom, above,below, vertical, horizontal, clockwise, and counterclockwise) are onlyused for identification purposes to aid the reader's understanding ofthe present disclosure, and do not create limitations, particularly asto the position, orientation, or use of the devices. Joinder references(e.g., affixed, attached, coupled, connected, and the like) are to beconstrued broadly and can include intermediate members between aconnection of elements and relative movement between elements. As such,joinder references do not necessarily infer that two elements aredirectly connected and in fixed relationship to each other. It isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative only andnot limiting. Changes in detail or structure can be made withoutdeparting from the spirit of the disclosure as defined in the appendedclaims.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

What is claimed is:
 1. A catheter comprising the following: an elongatedbody extending along a body longitudinal axis, said elongated bodycomprising a proximal catheter shaft section; a distal, deflectablecatheter shaft section; and an intermediate catheter shaft sectionextending between said proximal catheter shaft section and saiddeflectable catheter shaft section; first and second pull wires, whereineach of said first and second pull wires comprises a proximal end and adistal end, and wherein each of said first and second pull wires extendsalong said proximal catheter shaft section, along said intermediatecatheter shaft section, and along said deflectable catheter shaftsection; first and second compression coils around said first and secondpull wires, respectively, along said proximal catheter shaft section,and wherein each of said first and second compression coils comprises aproximal end and a distal end; a proximal shaft coupler disposed betweensaid proximal catheter shaft section and said intermediate cathetershaft section; a distal shaft coupler disposed between said intermediatecatheter shaft section and said deflectable catheter shaft section; anda bendable stiffening member positioned adjacent a distal portion ofsaid distal shaft coupler and around said second pull wire.
 2. Thecatheter of claim 1 further comprising, a handle assembly at a proximalend of said proximal catheter shaft section, and wherein said proximalends of said first and second compression coils nonfixedly abut aportion of said handle assembly, and wherein said distal ends of saidfirst and second compression coils nonfixedly abut a proximal portion ofsaid proximal shaft coupler.
 3. The catheter of claim 2 furthercomprising third and fourth compression coils around said first andsecond pull wires, respectively, along said intermediate catheter shaftsection, wherein each of said third and fourth compression coilscomprises a proximal end and a distal end, wherein said proximal ends ofsaid third and fourth compression coils nonfixedly abut a distal portionof said proximal shaft coupler, and wherein said distal ends of saidthird and fourth compression coils nonfixedly abut a proximal portion ofsaid distal shaft coupler.
 4. The catheter of claim 1, wherein saidbendable stiffening member includes a spring pack comprising a coilspring and a coil support tube.
 5. The catheter of claim 4 wherein saidcoil spring comprises a single-pitch coil, and wherein said coil supporttube extends around an outer surface of at least a portion of saidsingle-pitch coil.
 6. The catheter of claim 4, wherein said coil springcomprises a multi-pitch coil, and wherein said coil support tube extendsaround an outer surface of at least a portion of said multi-pitch coil.7. The catheter of claim 4, wherein said coil spring comprises amulti-pitch coil constructed from a single wire and including includestwo spaced-coil portions separated by a centrally-located, stacked-coilportion.
 8. The catheter of claim 4, wherein said coil spring comprisesa multi-pitch coil constructed from a single wire defining first,second, and third pitches, wherein said first pitch is larger than saidsecond and third pitches, and wherein said third pitch is larger thansaid second pitch.
 9. The catheter of claim 1, wherein said multi-pitchcoil spring comprises five sections including first and fifth sectionseach comprising coils with said first pitch, second and fourth sectionseach comprising coils with said second pitch, and a third sectioncomprising coils with said third pitch, and wherein said coil supporttube extends around an outer surface of said second, third, and fourthsection of said multi-pitch coil.
 10. The catheter of claim 1, wherein,prior to assembly of said elongated body, said distal shaft couplercomprises a component separate from said intermediate catheter shaftsection and separate from said deflectable catheter shaft section. 11.The catheter of claim 1, wherein said distal shaft coupler comprisespart of said deflectable catheter shaft section.
 12. The catheter ofclaim 1, wherein said distal shaft coupler is assembled with saiddeflectable catheter shaft section.
 13. The catheter of claim 1 furthercomprising, a handle assembly at a proximal end of said proximalcatheter shaft section, and wherein said handle assembly is coupled witha proximal end of said intermediate catheter shaft or a proximal end ofsaid proximal shaft coupler.
 14. The catheter of claim 1, said proximalcatheter shaft section further comprising a portion of a handle assemblyconfigured to receive said proximal shaft coupler.